SCIENCE - 1st QUARTER

• Human Gas Exchange


  Oxygen from inhaled air diffuses into bloodstream through alveolar-capillary membrane; Carbon Dioxide from bloodstream diffuses out into lung tissue
• Bronchi


  Branch off from the trachea, leading to the lungs
• Trachea


  The principal airway that connects the pharynx to the bronchi
• Alveoli


  Site of gas exchange (O2 & CO2) in the lungs
• Diffusion


  The process by which gases move through cell membranes
• Respiratory Muscles


  The muscles used for inhalation and exhalation
• Respiratory Reflexes


  The body's automatic response to irritation or stimulation in the airways and lungs
• Emphysema


  Damage to lung tissue, reducing elasticity
• Pleura


  A double-layered sac surrounding the lungs
• Pneumonia


  Infection affecting lung tissue
• Air is approximately 78 percent nitrogen and 21 percent oxygen, the remaining 1 percent are gases present in trace amounts
• The difference between Respiration and Breathing; Respiration is the overall exchange of gases between the atmosphere, Breathing is just a phase in Respiration
• The 4 phases of Respiration: Breathing, External Respiration, Internal Respiration, Cellular Respiration
• Lenticels - small holes in the bark of a tree that allow gases to pass through
• Pathway of oxygen to the lungs: nose - pharynx - larynx - trachea - bronchi - bronchioles - alveoli